GLP-1 for Cardiovascular Disease Risk

Cardiovascular disease — narrowed coronary arteries, heart attacks, strokes, failing hearts, poor circulation in the limbs — kills more people than anything else, an estimated 17.9 million a year. Most acute events trace back to atherosclerosis, the slow accumulation of lipid-rich plaque inside arterial walls. What accelerates it is familiar: raised blood pressure, diabetes, poor lipids, smoking, inactivity and excess weight.

Excess weight is not merely correlated here; it drives risk independently. Visceral fat in particular sustains low-grade inflammation, insulin resistance, an atherogenic lipid pattern and higher blood pressure, each of which speeds plaque formation and stiffens arteries. For decades no weight-loss drug had ever been shown to reduce cardiovascular events — and several older ones were pulled from the market for causing cardiac harm, which is worth remembering when reading what follows.

That record changed with this class. Developed first for type 2 diabetes, these drugs cut major adverse cardiovascular events across a series of large, well-run outcomes trials. In 2024 the FDA granted Wegovy a dedicated cardiovascular risk-reduction indication on the strength of results in people without diabetes — the first time an obesity medication had earned one.

The earliest signals came from the diabetes outcomes trials the FDA had required since the rosiglitazone episode of 2008. LEADER [2] followed 9,340 adults who had type 2 diabetes and stood at high cardiovascular risk, over a median 3.8 years; liraglutide 1.8 mg cut a composite of death from cardiovascular causes, heart attack short of fatal and stroke short of fatal by 13% against placebo. It was the first trial in this class to show superiority rather than simply rule out harm — a distinction that matters, because ruling out harm was all these trials were originally designed to do.

SUSTAIN-6 [3] tested weekly semaglutide in 3,297 adults with diabetes at high risk across two years and cut those same events by 26%, with a particularly marked reduction in non-fatal stroke. REWIND [4] then examined dulaglutide in 9,901 patients, deliberately including more people at only moderate risk than earlier trials had, and over a median 5.4 years cut events by 12% — extending the finding to a much broader slice of the diabetes population.

Pooling seven of these trials, a 2019 meta-analysis [5] put the class effect at a 14% reduction in major events, 12% in cardiovascular death and 16% in fatal or non-fatal stroke among people with diabetes at raised cardiovascular risk. An earlier pooled analysis [6] had reached consistent conclusions. The benefit held most consistently among the drugs with established atherosclerotic indications.

SELECT [1] is the trial that changed who this applies to. It enrolled 17,604 adults aged 45 and over who had established cardiovascular disease — a previous heart attack, stroke or symptomatic peripheral artery disease — a BMI of 27 or above, and no type 2 diabetes. Over a median 34.2 months, semaglutide 2.4 mg cut major events by 20%, with absolute rates of 6.5% against 8.0% on placebo. Two details carry the weight: the benefit appeared across prespecified subgroups, and the curves separated early, before much difference in body weight had accumulated. That timing implies cardiovascular mechanisms working alongside the weight loss rather than only through it, and it produced the March 2024 approval.

Wegovy holds a separate approval covering the reduction of serious cardiac events, for adults carrying established heart disease alongside either obesity or a BMI from 27 upward. Established disease means one already on record — a heart attack, a stroke, or peripheral artery disease with symptoms. Not risk factors, and not family history. This indication comes straight from the SELECT population and stands apart from the weight-management one.

Anyone with type 2 diabetes and high cardiovascular risk may qualify instead through the diabetes-labeled products, since semaglutide, liraglutide and dulaglutide all carry cardiovascular labeling earned in their outcomes trials. What the Wegovy indication adds is the group those never reached: people carrying excess weight and known disease who never became diabetic. Primary prevention — risk factors without a prior event — falls outside all of these approvals, and that boundary is worth stating plainly to patients rather than blurring.

In SELECT the benefit sat on top of everything else: most participants were already on statins, blood-pressure drugs and antiplatelet therapy. These drugs are an addition to guideline-directed treatment, not a substitute for it, and nobody with established disease should drop a proven cardiovascular medication in favor of one. The side-effect picture matches the obesity indication — nausea, vomiting and stomach discomfort, worst while the dose climbs and easing after.

Heart failure with reduced ejection fraction is a different and much weaker case; dedicated trials are still running, and what randomized evidence exists in that phenotype is not encouraging. Recent acute coronary syndrome, heart failure that has decompensated, or a serious rhythm disturbance all mean starting only in close coordination with a cardiologist. Lifestyle work — diet, activity, stopping smoking, limiting alcohol — remains the foundation none of this replaces. And cost and access are genuine obstacles, particularly at the 2.4 mg dose that SELECT actually used.